SensorManager.getRotationMatrix在Android模擬器上始終返回false

Question

我嘗試在我的Android模擬器上獲取方向SensorManager.getOrientation。在此之前，我使用SensorManager.getRotationMatrix來獲得旋轉矩陣，但這總是返回false。 這裏是我的代碼活動：

public class MainActivity extends Activity implements SurfaceHolder.Callback, View.OnClickListener{
 

public final static String DEBUG_TAG = "MainActivity"; 

private SensorManager sensorManager; 
private SurfaceView preview; 
private float[] mGravs; 
private float[] mGeoMags; 
private float[] mRotationM; 
private float[] mOrientation; 

private Sensor mAccelerometer; 
private Sensor mMagneticField; 

@Override 
protected void onCreate(Bundle savedInstanceState) 
{ 
    super.onCreate(savedInstanceState); 
    getWindow().addFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN); 
    requestWindowFeature(Window.FEATURE_NO_TITLE); 

    setContentView(R.layout.activity_main); 

    preview = (SurfaceView)findViewById(R.id.SurfaceView1); 

    sensorManager = (SensorManager)getSystemService(SENSOR_SERVICE); 

    mAccelerometer = sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER); 
    mMagneticField = sensorManager.getDefaultSensor(Sensor.TYPE_MAGNETIC_FIELD); 

    mGravs = new float[3]; 
    mGeoMags = new float[3]; 
    mRotationM = new float[16]; 
    mOrientation = new float[3]; 

    List<Sensor> sensorList = sensorManager.getSensorList(Sensor.TYPE_ALL); 
    for (int nI = 0; nI < sensorList.size(); nI++) { 
     Log.d(DEBUG_TAG, sensorList.get(nI).getName()); 
    } 
} 

private SensorEventListener sensorEventListener = new SensorEventListener() { 
    @Override 
    public void onSensorChanged(SensorEvent event) 
    { 
     synchronized (this) { 
      switch (event.sensor.getType()) { 
      case Sensor.TYPE_ACCELEROMETER: 
       System.arraycopy(event.values, 0, mGravs, 0, 3); 
       break; 
      case Sensor.TYPE_MAGNETIC_FIELD: 
       System.arraycopy(event.values, 0, mGeoMags, 0, 3); 
       break; 
      default: 
       return; 
      } 
      if (mGravs != null && mGeoMags != null) { 
       boolean bSuccess = SensorManager.getRotationMatrix(mRotationM, null, mGravs, mGeoMags); 
       if (bSuccess) { 
        SensorManager.getOrientation(mRotationM, mOrientation); 
       } 
      } 
     } 
    } 

    @Override 
    public void onAccuracyChanged(Sensor sensor, int accuracy) { 
     // TODO Auto-generated method stub 

    } 
}; 

private boolean openHardware() 
{ 
    sensorManager.registerListener(sensorEventListener, mAccelerometer, SensorManager.SENSOR_DELAY_NORMAL); 
    sensorManager.registerListener(sensorEventListener, mMagneticField, SensorManager.SENSOR_DELAY_NORMAL); 
    return true; 
} 

private void closeHardware() 
{ 
    sensorManager.unregisterListener(sensorEventListener); 
} 

@Override 
protected void onResume() 
{ 
    super.onResume(); 
    openHardware(); 
} 

@Override 
protected void onPause() 
{ 
    super.onPause(); 
    closeHardware(); 
} 

@Override 
protected void onStop() 
{ 
    closeHardware(); 
    super.onStop(); 
} 
} 

好吧，這個問題的發生是因爲磁場傳感器總是返回[0.0，0.0，0.0]。 如何讓磁場傳感器返回其他東西？

Answer 1

我有同樣的問題。一切都得到了假

這個答案已經幫我：https://stackoverflow.com/a/14224122/1549127